Justification and Persuasion about Cloning: Arguments in Hwang's Paper and Journalistic Reported Versions

We examine the argumentative structure of Hwang et al.'s (2004) paper about human somatic cell nuclear transfer (SCNT, or "therapeutic cloning"), contrasted with four Journalistic Reported Versions (JRV) of it, and with students' summaries of one JRV. As the evaluation of evidence is one of the critical features of argumentation (Jimenez-Aleixandre 2008), the analysis focuses on the use of evidence, drawing from instruments to analyze written argumentation (Kelly et al. 2008) and from studies about the structure of empirical research reports (Swales 2001). The objectives are: 1) To examine the use of evidence and the argumentative structure of Hwang et al.'s "Science", 303: 1669-1674 (2004) original paper in terms of the criteria: a) pertinence of the evidence presented to the claims; b) sufficiency of the evidence for the purpose of supporting the claims; and c) coordination of the evidence across epistemic levels. 2) To explore how the structure of Hwang's paper translates into the JRV and into university students' perceptions about the evidence supporting the claims. The argumentative structure of Hwang's paper is such that its apparently ostensible main claim about NT constitutes a justification for a second claim about its therapeutic applications, for which no evidence is offered. However, this second claim receives prominent treatment in the JRV and in the students' summaries. Implications for promoting critical reading in the classroom are discussed.